From ba0d09b6c42d6af7222dcdb9bbba276596bc3ce7 Mon Sep 17 00:00:00 2001
From: Athanasios Xygkis <athanasios.xygkis@epfl.ch>
Date: Sun, 20 Sep 2020 20:38:36 +0200
Subject: [PATCH] Compile C with C++ files together

---
 template_cpp/src/CMakeLists.txt  |  2 +-
 template_cpp/src/include/hello.h | 13 +++++++++++++
 template_cpp/src/src/hello.c     | 11 +++++++++++
 template_cpp/src/src/main.cpp    |  9 +++++++++
 4 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 template_cpp/src/include/hello.h
 create mode 100644 template_cpp/src/src/hello.c

diff --git a/template_cpp/src/CMakeLists.txt b/template_cpp/src/CMakeLists.txt
index c1d306a..14756e8 100644
--- a/template_cpp/src/CMakeLists.txt
+++ b/template_cpp/src/CMakeLists.txt
@@ -1,7 +1,7 @@
 # DO NAME THE SYMBOLIC VARIABLE `SOURCES`
 
 include_directories(include)
-set(SOURCES src/main.cpp)
+set(SOURCES src/main.cpp src/hello.c)
 
 # DO NOT EDIT THE FOLLOWING LINE
 find_package(Threads)
diff --git a/template_cpp/src/include/hello.h b/template_cpp/src/include/hello.h
new file mode 100644
index 0000000..b41ec3f
--- /dev/null
+++ b/template_cpp/src/include/hello.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+
+void hello();
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/template_cpp/src/src/hello.c b/template_cpp/src/src/hello.c
new file mode 100644
index 0000000..ecaf0d2
--- /dev/null
+++ b/template_cpp/src/src/hello.c
@@ -0,0 +1,11 @@
+#include "hello.h"
+
+void hello() {
+    printf("Source file that end in .c will be compiled automatically with gcc,\n"
+           "while files that end in .cpp will be compiled automatically with g++.\n"
+           "For those that prefer C, they can either use the provided C++\n"
+           "argument parser and write everything else in C, or delete the\n"
+           "provided main.cpp and start from scratch.\n"
+           "Make sure to have compatible ABI when calling C functions from cpp:\n"
+           "See `hello.h` on how to do this.\n");
+}
diff --git a/template_cpp/src/src/main.cpp b/template_cpp/src/src/main.cpp
index 52a5f16..c736a8c 100644
--- a/template_cpp/src/src/main.cpp
+++ b/template_cpp/src/src/main.cpp
@@ -4,8 +4,10 @@
 
 #include "barrier.hpp"
 #include "parser.hpp"
+#include "hello.h"
 #include <signal.h>
 
+
 static void stop(int) {
   // reset signal handlers to default
   signal(SIGTERM, SIG_DFL);
@@ -32,6 +34,9 @@ int main(int argc, char **argv) {
   Parser parser(argc, argv, requireConfig);
   parser.parse();
 
+  hello();
+  std::cout << std::endl;
+
   std::cout << "My PID: " << getpid() << "\n";
   std::cout << "Use `kill -SIGINT " << getpid() << "` or `kill -SIGTERM "
             << getpid() << "` to stop processing packets\n\n";
@@ -81,5 +86,9 @@ int main(int argc, char **argv) {
 
   std::cout << "Broadcasting messages...\n\n";
 
+  while (true) {
+    std::this_thread::sleep_for(std::chrono::seconds(60));
+  }
+
   return 0;
 }